New variable in KP Cas field?

While inspecting preliminary data of KP Cas obtained here, I noticed USNO-A2.0 1500-00673609 in some sort of minimum. Since it can be some side effect of aperture photometry data will be analyzed more precisely. I also like to ask other ones observing this field to check for variability on their images. I include image and light curves.

North up, west right. KP Cas in center of field, new var(?) marked...

Light curve of marked star during second run.

First night the USNO star was constant...